Over Boosting Then Under Boosting

[markyp2000]

hi all need help my 1998 turbo 2000 was over boosting i hit fuel cut off looked on some forums on here saying clean boost control valve out witch i did & didnt work now only boosting to 10 to 12 psi was at 15ish i have also changed the boost control valve still no good iv presure/vacumem tested the wastgate and the pipe work no signs of leaks also manifold pressure is also very low on boost only 10psi also tested presure at wastgate when boosting and is the same presure 10psi i removed the down pipe to check the turbo seems all ok on exhaust side havent checked inlet side due to to much work to get the pipe off CAN ANY ONE HELP

[20withascooby]

have you posted in the technical section

[Deano 666]

hi all need help my 1998 turbo 2000 was over boosting i hit fuel cut off looked on some forums on here saying clean boost control valve out witch i did & didnt work now only boosting to 10 to 12 psi was at 15ish i have also changed the boost control valve still no good iv presure/vacumem tested the wastgate and the pipe work no signs of leaks also manifold pressure is also very low on boost only 10psi also tested presure at wastgate when boosting and is the same presure 10psi i removed the down pipe to check the turbo seems all ok on exhaust side havent checked inlet side due to to much work to get the pipe off CAN ANY ONE HELP

hi have you changed anything on the car before this problem started?? or did it just loose boost??

[markyp2000]

nope just doing about 80mph went to over take and then hit cut off dun it 3 times so then i slowed down so as not to over boost

[20withascooby]

it hasnt gone into safe mode has it ???

[Pele]

By boost control valve do you mean the boost solenoid? If not try giving that a clean with some brake ceaner, sorted out my 'hitting a wall' problem Also check and double, triple check all air hoses, I had the problem recently and drove around for weeks with no boost and the CEL on then had another look - in the dark with a torch would you believe lol and it was one of the small air hoses on top of the engine split right on the connector....

[markyp2000]

not shore about save mode has it got it then + engine light isnt on. as for an air leak have cheaked small pipes but not the solid ones under the intercooler etc will do that later wen it cooled down (boost contol vave on o/s/f strut mount)

[20withascooby]

unplug battery for a about a hour that should reset the ecu

[markyp2000]

i will try that thats an easy thing to do first costs nothing lol